Separation of liquids

Abstract

In photographic processing apparatus, different processing solutions are normally contained in separate tanks, the material being processed as it passes from one tank to another through the required processing stages. This means that the apparatus needs to have a tank for each solution which is required for a particular process. Described herein is an arrangement in which more than one processing tank may be provided in a single container. The arrangement comprises tray which is divided into two portions by barrier means, each portion containing a different processing solution. The barrier means, includes an air bubble retained on the underside of a curved member which is maintained in a central position due to the liquid pressure on each side of the barrier means.

We claim: 
     
       1. A method of processing photographic material in a plurality of processing solutions, the method comprising the steps of: providing a plurality of processing solutions;   forming an interface between two adjacent processing solutions;   separating two adjacent processing solutions at the interface;   passing the photographic material from one processing solution to another adjacent processing solution through the interface formed between the two adjacent solutions;   characterized in that the method further comprises the steps of forming a bubble at the interface and maintaining the bubble to separate the two processing solutions.   
     
     
       2. A method according to claim 1, wherein the bubble is a gas bubble. 
     
     
       3. A method according to claim 2, wherein the gas is inert. 
     
     
       4. A method according to claim 2, wherein the gas is air. 
     
     
       5. A method according to claim 1, wherein the bubble is pressurized due to the static head of liquid on either side thereof. 
     
     
       6. Apparatus for separating liquids at an interface characterized in that a chamber is provided at the interface in which a bubble is formed and maintained, the bubble providing the separation between the two liquids at the interface. 
     
     
       7. Photographic processing apparatus comprising a processing tank containing at least two processing solutions, two processing solutions meeting at an interface, characterized in that a bubble is formed and maintained in a chamber at the interface between the two processing solutions. 
     
     
       8. A method of separating liquids which meet at an interface, the method comprising the steps of: providing a chamber at the interface;   forming a bubble in the chamber at the interface; and   maintaining the bubble to prevent mixing of the liquids.